<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>MAp</title>
		<script>
			var m=new Map();
			m.set("dog","小狗");
			m.set("snake","蛇");
			m.set("dog","老狗");
			console.log(m.get("snake"));
			console.log(m.get("pig"));
			console.log(m.has("snake"));
			console.log(m);
		</script>
	</head>
	<body>
	</body>
</html>